A fast hybrid simulation approach of ion energy and angular distributions in biased inductively coupled Ar plasmas

Abstract

In this work, a two-dimensional hybrid model, which consists of a bulk fluid module, a sheath module and an ion Monte-Carlo module, is developed to investigate the modulation of ion energy and angular distributions at different radial positions in a biased argon inductively coupled plasma. The results indicate that when the bias voltage amplitude increases or the bias frequency decreases, the ion energy peak separation width becomes wider. Besides, the widths of the ion energy peaks at the edge of the substrate are smaller than those at the center due to the lower plasma density there, indicating the nonuniformity of the ion energy distribution function (IEDF) along the radial direction. As the pressure increases from 1 to 10 Pa, the discrepancy of the IEDFs at different radial positions becomes more obvious, i.e. the IEDF at the radial edge is characterized by multiple low energy peaks. When a dual frequency bias source is applied, the IEDF exhibits three or four peaks, and it could be modulated efficiently by the relative phase between the two bias frequencies. The results obtained in this work could help to improve the radial uniformity of the IEDF and thus the etching process.